Does any of you know of a good server-side tool for generating line-charts - command-line tool will suffice (one that spits out a JPG, SVG, PNG or such)
Something integrated in Ruby would be even nicer 
- Carsten
Gruff (http://rubyforge.org/projects/gruff/)) or Scruffy (http://scruffy.rubyforge.org/)
Best regards
Peter De Berdt
Or, maybe you could use something like google charts:
There are some rails wrappers:
http://code.google.com/p/google-charts-on-rails/ http://code.google.com/p/gc4r/http://code.google.com/p/google-charts-on-rails/
or you can just roll your own fairly easily. Whether you can generate/ reference such google charts in your app in real-time by the client's browser or pre-fetched and stored on the server depends on your app needs/usage.
Jeff
ziya gives you great looking swf graphs.
Instructions to install the gem and samples: